If you look at when Jackfrags tried to snipe the plane, the curvature was insane. It barely went up and did a hard curve like a noob tube on COD. Its a very brief moment since he scopes out and start running, but you'll be able to see it if you look for it. I dont think these shots will be remotely possible with any type of skill.. it would have to be pure luck where hit someone without them even being in scope. I did however, notice the quick reload system they brought to BF4 actually works historically for this game. If you rewatch the sniper video and just pay attention, if you reload on empty, you'll load a clip into the mag well real fast, but if you reload before you empty, you'll put in one bullet at a time as if you were loading a pump action shotgun.
http://www.vg247.com/2016/06/13/battlefield-1-operations-mode-is-a-continuous-battle-across-multiple-maps/
Operations mode sounds crazy... hopefully it will work as intended... that one BF4 mode they tried to introduce was kinda crap. I think it was called chain link or something.